The invention relates to a method for protection of a limited local area against electromagnetic radiation, in particular the electromagnetic radiation that occurs when a mobile radio terminal is transmitting. The invention further relates to a radio station and to a mobile radio terminal.
Modern cellular mobile radio systems, such as the popular GSM system, are comprised of a large number of mobile switching centers that are networked to one another and produce access to a fixed network PSTN. Furthermore, the mobile switching centers are each connected to at least one base station controller. Each base station controller is in turn connected to at least one base station (base transmitting/receiving station). Such a base station is a radio station which can set up a radio link to other radio stations, so-called mobile stations (mobile radio terminals) via a radio interface.
For the purposes of this application, the term radio station also covers a base station, a (mobile radio) transmitting/ receiving device, a base transmitting/receiving station, and a radio station which at least partially operates on the principle of a base transmitting/receiving station for one or more mobile radio systems and has appropriate transmitting, receiving and processing devices.
The physical transmission resources for the radio path are assigned to logic mobile radio channels in accordance with a defined scheme and using a multiple access method such as a TDMA, FDMA, or a CDMA method. In principle, there are two types of logic mobile radio channel: signaling channels for transmitting signaling information, and traffic channels for transmitting wanted data, i.e. useful data. The logic mobile radio channels may be assigned to a specific link between a base station and a mobile station. Data can be transmitted between the mobile stations and the base station associated with these mobile stations by means of radio-frequency electromagnetic waves.
In many cases, this may be undesirable, particularly if these electromagnetic waves can interfere with other sensitive electronic equipment. For example, it is possible for the complex electronics in modern aircraft to be interfered with by the use of mobile telephones by passengers flying in the aircraft, which may lead to difficulties in controlling the aircraft. Some airlines and regulatory agencies therefore ban the use of mobile telephones. Currently, passengers are made aware of these dangers by a corresponding announcement and they are requested not to use their mobile telephones. In most cases the mobile telephones are then switched off manually by the mobile-telephone users. This prior art procedure is very complex and, naturally, quite unreliable.
It is accordingly an object of the invention to provide a method of protecting a limited local area against electro-magnetic radiation emitted by mobile radio terminals, a corresponding radio station and a mobile radio terminal, which overcome the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which allows a limited local area to be protected against electromagnetic radiation in a simple, efficient and reliable manner.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method of protecting a limited local area against electro-magnetic radiation emitted by mobile radio terminals, which comprises:
emitting signaling information with a transmitting device about a location area associated with the transmitting device;
causing, upon a reception and processing in a mobile radio terminal, an emission of second signaling information for updating the location area of the mobile radio terminal;
receiving the second signaling information with a receiving device; and
processing the second signaling information for detecting mobile radio terminals that are not switched off.
The invention is accordingly based on the idea of deliberately emitting signaling information in the area to be monitored in order to synthetically create conditions which force the mobile radio terminals to be detected to transmit signaling information, and processing of this signaling information leads to detection of mobile radio terminals which are not switched off.
If a radio station transmits signaling information over the location area associated with the radio station, whose reception and processing in a mobile radio terminal forces signaling information to be emitted in order to update the location area, then it is possible for mobile radio terminals which are not switched off to be actively required to emit signaling information by means of which they can easily be detected. Already known signaling procedures can be used for this purpose.
The invention makes it possible, simply and reliably, to identify whether or not there are any mobile radio terminals that are not switched off in an area to be monitored, and allows appropriate measures to be taken to protect a limited local area against electromagnetic radiation.
Mobile radio terminals also exist which interchange information with the mobile radio system at specific time intervals even in the standby mode. For the purposes of this application, switching off thus also means that the mobile radio terminal is switched to a state in which it can no longer emit any signals which could lead to significant interference with other electronic equipment.
In accordance with an added feature of the invention, the processing step comprises displaying information about the mobile radio terminals that are not switched off.
In accordance with an additional feature of the invention, the emitting step comprises emitting with the transmitting device a plurality of different signaling information items corresponding to different mobile radio systems, and the receiving step comprises receiving with the receiving device a plurality of different signaling information items corresponding to different mobile radio systems.
In other words, the radio station is operated at least partially on the principle of a base transmitting/receiving station for different mobile radio systems.
This means that the invention may be used in different countries, and mobile radio terminals of all persons and of the corresponding different mobile radio systems can be detected in monitoring areas which are generally entered by an international population (airports).
In accordance with another feature of the invention, the transmitting device transmits, after a fixed or variable time interval, signaling information about a changed location area associated with the transmitting device.
It is thus possible even for a mobile radio terminal which has already been detected and is switched on again after having first been switched off to emit signaling information relating to the change in the location area.
In accordance with a further feature of the invention, the transmitting device and/or the receiving device is/are not connected to switching centers.
Advantageously, the radio station operates at least partially on the principle of a base transmitting/receiving station of a mobile radio system that is not to be connected to switching centers. This means that the radio station can be designed to be technically very simple, cheap, and even to be portable.
In accordance with again an added feature of the invention, the transmitting device and the receiving device are integrated in a base transmitting/receiving station which at least partially operates on a principle of different mobile radio systems.
In accordance with again an additional feature of the invention, the signaling information emitted by the transmitting device is received only with those mobile radio terminals that have a specific physical relationship with the transmitting device.
This has the advantage that the only mobile radio terminals which are detected are those located in the area monitored by the invention.
In accordance with again another feature of the invention, the method further comprises:
causing with the processing of the second signaling information an emission of third signaling information via a radio interface using the principle of a mobile radio channel;
receiving the third signaling information with a mobile radio terminal; and
processing the third signaling information with programmable processor devices, and deactivating at least one transmission function of the mobile radio terminal.
In accordance with again a further feature of the invention, signaling information is transmitted for deactivating a transmission function after a first signaling phase of setting up a connection.
In accordance with yet again a further feature of the invention, the mobile radio terminal is placed into a state in which at least one transmission function is deactivated, and it can no longer be activated as long as the mobile radio terminal is in the state.
With the above and other objects in view there is also provided, in accordance with the invention, a radio station, comprising:
a transmitting device for transmitting signaling information over a location area, wherein the signaling information is not emitted at the same time by an adjacent base transmitting/ receiving station, and wherein a reception and processing of the signaling information in a mobile radio terminal leads to the emission of second signaling information;
a receiving device for receiving the second signaling information transmitted by the mobile radio terminals for updating the location area;
a processing device connected to the receiving device for processing the second signaling information; and
a display device connected to the processing device for displaying information about mobile radio terminals in the location area that are not switched off.
In accordance with yet an added feature of the invention, the transmitting device is adapted to emit, after a fixed or variable time interval, changing signaling information over a location area.
In accordance with yet an additional feature of the invention, the radio station is not connected to a switching center.
In accordance with yet another feature of the invention, the transmitting device, the receiving device, and the processing device are designed to process signaling information for different mobile radio systems.
With the above and other objects in view there is also provided, in accordance with a concomitant feature of the invention, a mobile radio terminal, comprising:
a receiving device for receiving signaling information;
programmable processor devices connected to the receiving device for processing the signaling information; and
means for deactivating at least one transmission function of the mobile radio terminal as a function of the received and processed signaling information.
In another, above-mentioned refinement of the invention, signaling information is emitted by a radio station via a radio interface, which signaling information is received and processed by a mobile radio terminal, and this process leads to deactivation of a transmission function of the mobile radio terminal.
This means that the handling of mobile radio terminals is limited automatically, reliably and efficiently to those functions which cause no interference with the environment. It is no longer required that the apparatus is manual switched off.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for protection of a limited local area against electromagnetic radiation emitted by mobile radio terminals, a radio station and a mobile radio terminal, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.